The adoptive mother of Jacob and The Man in Black also known as "Mother". She was the protector of the Island and The Source before Jacob. The Man in Black believed her to be insane, however he shares her low opinion of people (citing their greed and manipulative nature as evidence.) Even thousands of years later, the Man in Black blames Mother for his unresolved issues. (Recon)

Approximately 2000 years before the crash of Oceanic Flight 815, Mother encountered a young pregnant woman named Claudia who had been shipwrecked on the island and separated from her people. She took care of Claudia and assisted in the delivery of her twins. Immediately after giving birth to the younger twin - before Claudia could even name the second child - she bludgeoned Claudia to death with a rock. She raised the boys on the island as her own, not sharing with them her secrets until she felt they were ready, including the fact that she was not their biological mother. She had a general disdain for people, as she told her boys "They come, they fight, they destroy, they corrupt. It always ends the same." She prevented her sons from interacting with the other inhabitants of the island, presumably Claudia's fellow castaways.

When the boys were teenagers, she gave her younger son a senet board game which he intuitively knew how to play by examining the board. She also revealed to them The Source at the heart of the island and explained that one of them would become the guardian and protector of it after her. She also informed them that she had made it so the two boys could not harm each other. Although it was apparently not forbidden for them to fight, or even brutally beat each other, as Jacob was seen beating his brother at least two times after this revelation.

Neither of her sons knew who would be Mother's replacement, although Jacob believed that their mother preferred it be his brother. Her other son, however, from an early age had a strong desire to leave the island. Mother told her sons that there was nothing on the other side of the ocean; there was only the Island.

After seeing and talking to an apparition of Claudia, the Man in Black confronted Mother with the lies she had told, including his heritage. She admitted to lying, and he decided to leave Mother. He invited Jacob to join him, but Jacob remained with Mother while his brother left to live with the other inhabitants. Thus her mantle of protecting the Island and the Source was eventually passed to Jacob.

Years later, after the ritual in which Jacob became the protector of the Island, she visited her younger son, who she had learned from Jacob had been mining underground with his people to find another route to the source. After a discussion in which she failed to deter him from his course, she attacked him, rendering him unconscious. She then proceeded to fill in the well in which he had been working, and waylaid his companions and burned their village, effectively destroying his chances of immediate escape.

Enraged, the Man in Black returned to their home and killed her with a knife through her back. As she died, she thanked him. (Across the Sea)

When Jacob discovered her murder by his brother, he savagedly beat him and dragged him to The Source, recalling Mother's admonition doing so would result in something that was even worse than death. The Man in Black's body remained afterwards, and Jacob entombed his brother and Mother together in a cave, placing between them a pouch containing a white senet piece and a black senet piece.(Across the Sea)

She and her dead son were discovered approximately two thousand years later by Jack Shephard and Kate Austen as they were fleeing a swarm of bees nearby. John Locke dubbed the two bodies Adam and Eve. (House of the Rising Sun) Some time later, Hurley, not knowing who the skeletons actually belonged to, suggested that given the supernatural properties of the Island, the skeletons could have even belonged to themselves, deposited there during a time-travelling event. (Lighthouse)